The present invention relates generally to a tire pressure monitoring system, and more particularly, to a method and system for automatically detecting the identification of a spare tire.
Various types of pressure sensing systems for monitoring the pressure within the tires of an automotive vehicle have been proposed. Such systems generate a pressure signal using an electromagnetic (EM) signal, which is transmitted to a receiver. The pressure signal corresponds to the pressure within the tire. When the tire pressure drops below a predetermined pressure, an indicator is used to signal the vehicle operator of the low pressure.
Various tire manufacturers have suggested various locations for the pressure sensors. Known systems include coupling a pressure sensor to the valve stem of the tire. Other known systems and proposed systems locate the pressure sensors in various locations within the tire wall or tread. Tires are mounted to wheels that are commonly made from steel or aluminum.
For vehicles that have a full size spare, such as trucks and sport utility vehicles, the spare tire is likely to be included when rotating the tires. In the event that a spare tire is not monitored, at some point only three of the rolling tires may report a tire pressure. Many current systems are unable to identify the presence of a spare replacing a rolling tire and thus only three tires register pressures within the system.
It would be therefore be desirable to provide a tire pressure monitoring system that automatically updates when a spare tire replaces a rolling tire.